1. Field of the Invention
The present invention relates to an apparatus and method for mounting electronic parts onto a substrate.
2. Description of Related Art
U.S. Pat. No. 5,778,525 discloses a conventional component mounting apparatus having two mounting heads for picking up electronic parts from component supply tables and mounting them onto a substrate (circuit board).
This type of the mounting apparatus, a so-called two-beam type, generally handles several kinds of substrates with various sizes. Every time the size of the substrate is changed, some adjustments, for example, changing a transfer width between transfer rails, are carried out. In this case, the transfer width is generally changed by moving only one of the transfer rails along the direction of the transfer width.
Accordingly, the traveling distance of the beam equipped with the mounting head corresponding to the moved transfer rail is different from the traveling distance of another beam equipped with another mounting head corresponding to the fixed transfer rail. This difference causes mounting operations and sequences between these beams to be unbalanced, which may cause undesirable interferences and/or waiting time between these beams.